William e



(No Model.)

W. E. PRALL, Jr. MOTOR FOR STREET CARS.

No. 426,062. Patented Apr. 22, 1890.

WITNESSES:

'VVILLIAM E. PRALL, JR, OF WASHINGTON, DISTRICT OF COLUMBIA.

MOTOR FOR STREET-CARS.

SPECIFICATION forming part of Letters Patent No. 426,062, dated April 22, 1890.

I Application filed October 16, 1889. Serial No. 327,177. (No model.)

To aZZ whom it may concern:

Be it known that I, WILLIAM E. PRALL, J12, a citizen of the United States, and a resident of Washington, in the District of Columbia, have invented certain new and useful Improvements in Motors for Street-Cars and other Vehicles, of which the following is a specification.

This invention is an improvement on the construction shown and described in United States Letters Patent granted to me November 20, 1888, Serial No. 393,263, and is fully disclosed in the following specification, of which the accompanying drawing forms a part, and which represents a street-car provided with my improvement, certain portions thereof being shown in section.

In applying my apparatus to a car I prefer to adopt the general plan shown in the drawing, though it is evident that other arrangements may be made and that the motor may be applied to a separate cab, which may be employed to draw one or more cars, if necessary.

Referring to the drawing, A indicates a tank, filled, preferably, with superheated water; B, a steam generator and superheater, and C a steam-engine. These parts are preferably arranged as shown, the water-tank being under the rear portion of the car, and the steam generator and superheater between the axle and the engine under the front portion or platform. The steam generator and superheater consists of one or more coils of pipe arranged in a casing, preferably cylindrical in shape and properly covered to prevent radiation, the coil or coils being in communication with the water-tank and engine and arranged in the following manner:

A is a pipe communicating with the bottom of tank A and provided with a cup-shaped vessel G, and a check-valve a, and an ordinary valve to, and a by-pass 0, provided with a back-pressure safety-valve c. The pipes 12 of the separate steam-coils communicate with the top of the cup G and are provided with regulating or needle valves 6.

b are pipes which communicate with the pipes Z) and with tank A through by-pass c. The pipes 19 within the steam-generating chamber are arranged in conical spiral coils,

the upper end of the coil or spiral communicating with a steam-pipe I, which communicates with a steam-drum E. The steam-drum E is located within the escape-flue of the hotair or steam-generating chamber, or it may be between the latter and the engine, or at any other points desired, and a pipe M, provided with a valve m, connects the drum E with the top of the tank A.

H is a hydrocarbon or fuel tank, placed, preferably, at or on the top of the car, and h a pipe extending therefrom to a burner B, ofany preferred construction.

0 is a small pipe which communicates with the steam-drum and also with the burner B, whereby steam is conveyed to the burner to assist in the vaporization and combustion of the hydrocarbon in the well-known manner, if the same should be thought necessary, though with my construction of steam-generator it is not probable that the use of steam for this purpose would be required.

L is a pipe which forms a communication between the steam-drum and engine, and by which steam is supplied to the engine, and L an exhaust-pipe communicating with a condenser P on the top of the car. A lever S is provided with a rod R, which connects the lever S with valves or m in pipes L and M and valve 91/ in the fuel-supply pipe, and a small pipe E, provided with a safety-valve, connects the steam-drum with the exhaustpipe.

The car-axlc and crank-shaft of the engine are connected by means of a chain belt and gear-wheels in the well-known way.

As hereinbefore stated, the burner B may be of any preferred construction, adapted to the combustion of oil, vapor, oil and air, or oil and steam, or vapor and air or steam. I prefer, however, to arrange between the burner and steam-coils a layer of perforated firebrick or similar substance, which will receive the flame and direct heat from the burner in such a manner that nothing but hot air or the highly-heated gases of combustion will pass through the perforations in the fire-brick and come in contact'with the steam-coils, the object being to prevent the pipes from being overheated and destroyed in case the water is discharged from them, leaving them filled only with steam. I also contemplate the use, in connection with the construction shown and described herein, of a small ignition burner or jet, the same as in the patent hereinbefore referred to, whereby the main burner may be instantly ignited the moment the fuel-supply is turned on, the ignition-jets being always burning when the car is in use.

In the operation of this apparatus the tank A is filled at a station provided for the purpose, preferably with superheated water, but

may be filled with cold water, which would soon become heated by the passage of steam from the steam generator and superheater to the tank, as hereinafter described. lVhen the tank Ais filled, if the lever S be manipulated so as to open valves m, m, and n and valve a be opened, the water in tank A would by its own gravity be forced through pipe A into the cup G and through small valves e into the steam-coils. The water would seek the samelevel in the steamcoils as in tank A. At the same time the oil in tank H would pass through pipe h to the burner, and, being ignited, would begin the generation of steam within the coils. Valve m in pipe M being open, the steam would pass directly in to tank A, where it would maintain the same pressure as in the generator, the effect of which would be to cause the'water to maintain a level within the coils b, the same as that in tank A, at all times, whether the pressure be high or low, providing that the communicating valves a, m, and e are not so controlled as to prohibit a flow of water equal to thegeneration and utilization of steam. The steam in the drum E being at the same pressure as that in the coils and the valve m being open, the steam will pass to the engine. The passage of steam from the steam generator and superheater to the tank A through the pipe M also serves to heat the water in said tank or to keep the water at a high temperature it the same were heated before being placed in the tank, as hereinbefore stated. \Vhen it is desired to stop the engine, the lever S is manipulated so as to close the valves m, m, and 'n, and the flow of the steam to the engine and tank A through pipe M is cut,

off, as is also the flow of oil to the burner. If at this time the pressure in the coils should increase beyond the point desired, the steam or water will be forced back through pipes b and pipes a into tank A, and the pressure in the tank and coils will thus be equalized. The flow of oil to the burner being cut oif at the same time as the flow of steam to the engine, it is probable that there will never be any overpressure in the coils caused by cutting ofi the flow of steam to the engine. The pipe 0 is provided with a back-pressure safety or check valve so constructed as to allow the steam or water to be forced back into tank A whenever the pressure in the coils shall be excessive, as herein stated, and the reliefpipe E, connecting the steam drum and eX- haust, is intended as an additional means for relieving overpressure, the safety-valve therein being set for a pressure greater than that of o.

The check-valves, regulating-valves, and other details of construction may be of any preferred form, they constituting no part of this invention, and means for heating the car -by the exhaust-steam from the engine may also be provided.

It is evident that a single pipe maybe substituted for the numerous small pipes that enter the chamber G, and that said single pipe may be placed in direct communication with pipe A, or form a portion thereof, and that the steam-generator may be formed from a single coil; also, that many changes may be made in the construction, location, and operation of the various valves used in this apparatus and in the means for operating the same without departing from thespirit of this invention, and all such changes and others which relate merely to the details of construction and operation are considered as coming within the scope thereof.

Having fully described my invention, its construction and operation, what I claim, and desire to secure by Letters Patent, is

1. In a motor for street-cars and other vehicles, the combination, with a feed-water-supply tank, of a steam-generator and a steamengine, the steam-generator being supplied with water from the tank by a pipe communicating therewith, and a bypass consisting of a pipe 0, provided with a regulating-valve also forming a communication between the generator and the supply-tank, substantially as shown and described.

2. In a motor for street-cars and other vehicles, the combination of a hot-water-supply tank, a steam-generator in communication therewith, a fluid-fuel burner, and a steampipe communicating with the steam-drum and with the fluid-fuel supply, substantially as shown and described.

3. The combination, in a motor for streetcars and other vehicles, of a hot-water-supply tank, a steam-generator in communication therewith, a fluid-fuel burner, a pipe communicating with the hot-water-supply tank, and a steam-pipe communicating therewith and with the fluid-fuel supply, substantially as shown and described.

4:. In a motor for street-cars and other vehicles, the combination of a watersupply, a steam-generator in communication therewith, a steam-engine in communication with the generator by means of a pipe E, having a valve m, and a fluid-fuel burner supplied by a pipe h, having a valve a, said valves m and n beingoperated by a lever S, substantially as shown and described.

5. In a motor for street-cars and other vehicles, the combination, with a water-supply tank, of a steam-generatorin communication therewith, a pipe M, having a valve m, forming a communication between the supplytank and the generator, a steam-drum, and a steam-engine in communication therewith by means of a pipe E, having a valve m, said valves 9% and m being operated by a lever S, substantially as shown and described.

6. In a motor for street-cars and other vehicles, the combination of a water-supply tank, a steamgenerator in communication therewith by means of a pipe A, a steam-engine in communication with the generator by means of a pipe E, having a valve m, and a pipe M, provided with a valve m, forming a communication between the tank and the generator, said valves m and m being operated by a lever S, substantially as shown and described.

7. In a motor for street-cars and other vehicles, the combination of a water-supplytank, a steam-generator in communication therewith by means of a pipe A, a by-pass 0, also forming a communication between the supply-tank and the generator, a steam-engine in communication with the generator by means of a pipe E, having a valve m, and a pipe M, provided with a valve m, forming a communication between the tank and the generator, said valves m and m being operated bya lever S, substantially as shown and described.

8. In a motor for street-cars and other Vehicles, the combination of a water-supply tank, a steam-generator in communication therewith, a fluid-fuel burner supplied by a pipe 71, having a valve n, a steam-engine in communication with the generator by means of a pipe E, having a valve m, and a pipe forming a communication between the generator and the supply-tank, having a valve m, said valves m, n, and m being operated by a lever S, substantially as shown and described.

9. The combination, in a motor for streetcars and other vehicles, of a hot-water-supply tank, a steam-generator in communication therewith, a fluid-fuel burner supplied by a pipe 71, having a valve 91', an engine in communication with the generator by means of a pipe E, having a valve m, and a steam-pipe O, communicating with the fiuid-fuel supply, the valves n and m being operated by a lever S, substantially as shown and described.

10. In a motor for street-cars and other vehicles, the combination of a hot-water supply tank, a steam-generator in communication therewith, a steam-engine in communication with the generator, a fluid-fuel burner, and a steam-pipe O, communicating with the steamsupply and with the supply to the fluid-fuel burner, the fluid-fuel supply, and the steampipe communicating therewith, the communi' cation between the engine and the generator being controlled by cocks and valves, substantially as and for the purposes set forth.

Signed at New York city, in the county of New York and State of New York, this 12th day of October, A. D. 1889.

WVILLIAM E. PRALL, J R. Witnesses:

DANIEL E. DELAVAN, S. SMITH. 

